Optical fiber holder

ABSTRACT

Provided is an optical fiber holder comprising a holder body and a cover. The holder body has an accommodation section capable of accommodating a plurality of optical fibers. The holder body or the cover has at least one ridge which can be disposed within the accommodation section. When the cover is closed over the holder body, a plurality of sections which can parallelly accommodate the plurality of optical fibers are parallelly formed by the inner surface of the accommodation section, the lower surface of the cover, and the ridge.

TECHNICAL FIELD

The present invention relates to an optical fiber holder.

This application claims priority based on Japanese Patent ApplicationNo. 2016-176353 filed on Sep. 9, 2016, and all contents described in theJapanese Patent Application are incorporated by reference.

BACKGROUND ART

Patent literature 1 discloses an optical fiber holder including a firstarrangement groove for aligning a plurality of optical fiber core wiresin a holder body, a plurality of positioning grooves for converting anarrangement pitch of the optical fiber core wires in a longitudinaldirection of the first alignment groove, and a second arrangement groovehaving a width narrower than that of the first arrangement groove foraligning the optical fiber core wires removing a second coating layer ina longitudinal direction of the positioning grooves.

CITATION LIST Patent Literature

Patent literature 1: JP-A-2005-258129

SUMMARY OF INVENTION

An optical fiber holder according to an aspect of the present disclosureincludes:

a holder body;

a first lid; and a second lid, wherein

the holder body includes a housing portion that is configured to house aplurality of optical fibers,

the holder body includes at least one linear protrusion along alongitudinal direction of the holder body in the housing portion,

the housing portion includes a plurality of grooves that include aconstant groove width and that is configured to house the plurality ofoptical fibers in parallel respectively between the protrusion and aninner surface of the housing portion,

the plurality of optical fibers are configured to be held in parallelrespectively in the plurality of grooves in a state where the first lidis closed with respect to the holder body, and

the plurality of optical fibers are configured to be housed in a movablestate where the plurality of optical fibers are movable in parallelrespectively in the plurality of grooves, in a state where the secondlid is closed with respect to the holder body.

An optical fiber holder according to another aspect of the presentdisclosure includes:

a holder body; and

a lid, wherein

the holder body includes a housing portion that is configured to house aplurality of optical fibers,

the holder body or the lid includes at least one protrusion that iscapable of being disposed in the housing portion, and

a plurality of sections are formed in parallel such that the pluralityof sections are configured to house the plurality of optical fibers inparallel respectively by an inner surface of the housing portion, alower surface of the lid, and the protrusion in a state where the lid isclosed with respect to the holder body.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an optical fiber holder according to afirst embodiment.

FIG. 2 is a top view of the optical fiber holder according to the firstembodiment.

FIG. 3 is a side view of the optical fiber holder according to the firstembodiment viewed from a front of an optical fiber insertion direction.

FIG. 4 is a top view showing a state in which a first lid of the opticalfiber holder according to the first embodiment is closed with respect toa body.

FIG. 5 is a sectional view taken along line A-A in FIG. 4.

FIG. 6 is a top view showing a state in which the first lid and a secondlid of the optical fiber holder according to the first embodiment areclosed with respect to the body.

FIG. 7 is a perspective view showing an example of an optical fiberribbon before the optical fiber ribbon is inserted into the opticalfiber holder according to the first embodiment.

FIG. 8 is a top view showing a state in which a plurality of opticalfibers are inserted into the optical fiber holder according to the firstembodiment and the first lid is closed with respect to the body.

FIG. 9 is a partial enlarged sectional view taken along line B-B in FIG.8.

FIG. 10 is a perspective view showing an example of the optical fiberribbon after insertion into the optical fiber holder according to thefirst embodiment.

FIG. 11A is a schematic view showing an example in which a pitch of Vgrooves of a fusion machine or the like and an arrangement pitch ofoptical fibers are the same.

FIG. 11B is a schematic view showing an example of a case in which apitch of V grooves of a fusion machine or the like and an arrangementpitch of optical fibers are different.

FIG. 12A is a schematic view showing an example of a position of thepitch of the V grooves of the fusion machine or the like and a positionof the optical fibers, in a case where the optical fiber ribbon isdivided into a plurality of groups and sections through the groups areformed in parallel.

FIG. 12B is a schematic view showing an example of a position of thepitch of the V grooves of the fusion machine or the like and a positionof the optical fibers, in a case where a space between the groups of theoptical fiber ribbon is narrower than that in FIG. 12A.

FIG. 12C is a schematic view showing an example of a position of thepitch of the V grooves of the fusion machine or the like and a positionof the optical fibers in a case where a space between the groups of theoptical fiber ribbon is wider than that in FIG. 12A.

FIG. 13 is a perspective view of an optical fiber holder according to asecond embodiment.

FIG. 14 is a top view of the optical fiber holder according to thesecond embodiment.

FIG. 15 is a side view of the optical fiber holder according to thesecond embodiment viewed from a front of an optical fiber insertiondirection.

FIG. 16 is an enlarged view of a portion showing a protrusion and agroove provided in the holder body in FIG. 15.

FIG. 17 is a top view showing a state in which a plurality of opticalfibers are inserted into the optical fiber holder according to thesecond embodiment and a second lid is closed with respect to the body.

FIG. 18 is a top view showing a state in which a plurality of opticalfibers are inserted into the optical fiber holder according to thesecond embodiment and all lids are closed with respect to the body.

DESCRIPTION OF EMBODIMENTS Technical Problem

In recent years, as a diameter of an optical fiber is reduced, anoptical fiber which is normally used with an outer diameter of 0.25 mmhas been reduced in diameter, for example, an optical fiber having anouter diameter of 0.20 mm can be manufactured now. However, since apitch of V grooves of a fusion machine or the like that fuses opticalfiber ribbons with each other (or a plurality of optical fibers inparallel with each other) is 0.25 mm, a position of the optical fibersand a position of the V grooves are shifted when the optical fiberribbons with an arrangement pitch of 0.20 mm are fused with each other,and it is difficult to arrange the optical fibers in the V groovesreliably. In order to set the pitch of the V grooves to 0.20 mm, it isnecessary to newly design and manufacture a fusion machine or the likeand set the pitch of the V grooves to 0.20 mm by remodeling orexchanging the existing V groove portions of the fusion machine or thelike, which takes time and cost.

For example, even if an optical fiber holder in Patent literature 1 isused, it is difficult to arrange a plurality of optical fibers inparallel so as to correspond to the fusion machine or the like thatcorresponds to an arrangement pitch different from the arrangement pitchof the optical fibers before the optical fibers are held in the opticalfiber holder.

An object of the present disclosure is to provide an optical fiberholder in which a plurality of optical fibers can be arranged inparallel such that all of the optical fibers can be reliably placed in Vgrooves even using a fusion machine or the like including the V grooveswith an arrangement pitch different from the arrangement pitch of theplurality of optical fibers before the optical fibers are held in theoptical fiber holder.

Effect of the Disclosure

According to the present disclosure, a plurality of optical fibers canbe arranged in parallel such that all of the optical fibers can bereliably placed in the V grooves even by using the fusion machine or thelike that includes V grooves with an arrangement pitch different fromthe arrangement pitch of the plurality of optical fibers before theoptical fibers are held in the optical fiber holder.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

First, embodiments of the present invention is listed and described.

An optical fiber holder according to embodiments of the presentinvention includes:

(1) a holder body;

a first lid; and a second lid, wherein

the holder body includes a housing portion that is configured to house aplurality of optical fibers,

the holder body includes at least one linear protrusion along alongitudinal direction of the holder body in the housing portion,

the housing portion includes a plurality of grooves that include aconstant groove width and that is configured to house the plurality ofoptical fibers in parallel respectively between the protrusion and aninner surface of the housing portion,

the plurality of optical fibers are configured to be held in parallelrespectively in the plurality of grooves in a state where the first lidis closed with respect to the holder body, and

the plurality of optical fibers are configured to be housed in a movablestate where the plurality of optical fibers are movable in parallelrespectively in the plurality of grooves, in a state where the secondlid is closed with respect to the holder body.

According to the above configuration, the grooves of the housing portionare spaced from adjacent grooves by a degree of the width of theprotrusion, and a plurality of housed optical fibers are arranged inparallel at the space for each of the plurality of optical fibers.

Accordingly, even if a width of the entire optical fiber array isextended and the fusion machine or the like is used such that the fusionmachine or the like includes V grooves with an arrangement pitchdifferent from the arrangement pitch of the plurality of optical fibersbefore the plurality of optical fibers are held in the optical fiberholder, the plurality of optical fibers can be arranged in parallel suchthat all the optical fibers can be reliably placed in the V grooves.

(2) A height of the protrusion is 0.15 mm or above and 0.3 mm or below.

A guide function can be obtained and the operation can be easy whenoptical fibers having an outer diameter of 0.20 mm are put into thegrooves while handled with a ball of a finger, and overlapping of theoptical fibers in the grooves can be suppressed. Further, it is possibleto reliably hold the optical fibers having an outer diameter of 0.20 mm.

(3) A third lid is further included, and

the housing portion includes wide grooves and does not provide with theprotrusion at a covered position in a state where the third lid isclosed respect to the holder body.

By closing the third lid 41, the optical fibers can be held morereliably.

An optical fiber holder according to another embodiment of the presentinvention includes:

(4) a holder body; and

a lid, wherein

the holder body includes a housing portion that is configured to house aplurality of optical fibers,

the holder body or the lid includes at least one protrusion that iscapable of being disposed in the housing portion, and

a plurality of sections are formed in parallel such that the pluralityof sections are configured to house the plurality of optical fibers inparallel respectively by an inner surface of the housing portion, alower surface of the lid, and the protrusion in a state where the lid isclosed with respect to the holder body.

According to the above configuration, the sections of the housingportion are spaced from adjacent sections by a degree of the width ofthe protrusion, and the plurality of optical fibers inserted into thesections are arranged in parallel at the space for each of the pluralityof optical fibers.

Accordingly, a width of the entire optical fiber array is extendedbefore and after the insertion, and an averaged arrangement pitch of theoptical fibers after the insertion is wider than an arrangement pitchbefore the insertion. Therefore, the plurality of optical fibers can bearranged in parallel such that all of the optical fibers can becertainly placed in the V grooves even by using the fusion machine orthe like that includes V grooves with the arrangement pitch differentfrom the arrangement pitch of the plurality of optical fibers before theplurality of optical fibers are held in the optical fiber holder.

(5) The protrusion has a width of 0.17 mm or above and 0.27 mm or below.

When the optical fiber core wires with a pitch of 0.20 mm is placed inthe V grooves of the fusion machine or the like with a pitch of 0.25 mm,by setting the width of the protrusion to 0.17 mm or above and 0.27 mmor below, only one optical fiber core wire abuts on an inclined surfaceof each V groove and fits into the V groove along the inclined surface,so one optical fiber core wire can be placed in each V groove.

(6) A distance between centers of adjacent sections is 0.95 mm or aboveand 1.05 mm or below.

When optical fiber core wires with a pitch of 0.20 mm are placed in theV grooves of the fusion machine or the like with a pitch of 0.25 mm, bysetting the distance between the centers of the adjacent sections to0.95 mm or above and 1.05 mm or below, only one optical fiber core wireabuts on an inclined surface of each V groove and fits into the V groovealong the inclined surface, so one optical fiber core wire can be placedin each V groove.

(7) The holder body includes a section outer protrusion that is providedto be continuous from the protrusion on one side of the housing portionoutside the section,

widening side surfaces are provided on two both side surfaces in aninner side of the housing portion on one side outside the section suchthat the widening side surfaces are respectively continuous from sidesurfaces of sections, among the plurality of sections, on both sidesurfaces in the inner side of the housing portion, and

the widening side surfaces have a shape in which a space between thewidening side surfaces is extended along a longitudinal direction of thehousing portion as being away from the section.

Since the widening side surface extends as being away from the sectionalong the longitudinal direction of the housing portion, a width betweenthe widening side surface as an entrance for inserting the plurality ofoptical fibers and the section outer protrusion is wider than a width ofa section on the side surface side of the housing portion. Therefore,even when the width of the section is not much larger than the width ofthe plurality of optical fibers to be inserted, since the entrance iswider than the width of the section, it is easy to insert the pluralityof optical fibers from the entrance.

(8) A plurality of the protrusions are included,

the holder body includes, on one side outside the section of the housingportion, a plurality of section outer protrusions provided so as to becontinuous from the plurality of the protrusions respectively, and

the plurality of section outer protrusions have a shape in which a spacebetween adjacent section outer protrusions is extended along alongitudinal direction of the housing portion as being away from thesection.

Since the space between the adjacent section protrusions is extended asbeing away from the section along the longitudinal direction of thehousing portion, a width between ends of the adjacent section outerprotrusions is wider than the width of the section. Therefore, the widthbetween the ends of the section outer protrusions as the entrance forinserting the plurality of optical fibers is wider than the width of thesection between the adjacent protrusions. Therefore, even when the widthof the section is not much larger than the width of the plurality ofoptical fibers to be inserted, since the entrance is wider than thewidth of the section, it is easy to insert the plurality of opticalfibers from the entrance.

(9) The lid is provided with a tapered surface where the lower surfaceis recessed on one side end of the section in a longitudinal direction.

The upper surface (ceiling) of the entrance of the section is highertoward the outside of the section by the tapered surface provided on thelid. Therefore, the entrance portion of the section is extended upwardfrom the interior of the section, and the plurality of optical fibersare easily inserted from the entrance.

(10) A second lid is further included, and

a plurality of optical fibers housed in the housing portion and insertedinto the section are configured to be held in the housing portion in astate where the second lid is closed with respect to the holder body.

Since the second lid is closed with respect to the holder body, it ispossible to hold the plurality of optical fibers housed in the housingportion and inserted into the section.

Details of Embodiments of the Invention

A specific example of an optical fiber holder according to embodimentsof the present invention is described below with reference to thedrawings.

The present invention is not limited to these examples but is indicatedby the scope of claims, and is intended to include meanings equivalentto the scope of claims and all modifications within the scope.

In the following description, a front-rear direction, a left-rightdirection, and an up-down direction are directions of arrows shown asappropriate in the drawings.

First Embodiment

An optical fiber holder according to a first embodiment is described.

As shown in FIG. 1 and FIG. 2, the optical fiber holder 1 according tothe first embodiment includes a holder body 2 and a first lid 3. Theholder body 2 includes an housing portion 5 capable of housing aplurality of optical fibers (see FIG. 7 to FIG. 10 which are describedlater) such as a 12-core optical fiber ribbon. The housing portion 5 isa groove-shaped recess provided on an upper surface 2 c of the holderbody 2 from one end (front side end 2 b) of the holder body 2 in alongitudinal direction to the other end (rear side end 2 a).

As shown in FIG. 1 to FIG. 3, the first lid 3 is rotatably connected tothe holder body 2 via a hinge portion 3 a and can be opened and closedwith respect to the holder body 2. The optical fiber holder 1 includesat least one protrusion 6 at a position where the housing portion 5 iscovered when the first lid 3 is closed. The protrusion 6 is providedsuch that a longitudinal direction thereof is along the longitudinaldirection of the holder body 2, and in the first embodiment, a pluralityof protrusions 6 a, 6 b are provided in the holder body 2. Theprotrusion 6 may be provided on a lower surface 3 b of the first lid 3instead of the holder body 2 as long as it can be disposed in thehousing portion 5 when the first lid 3 is closed (FIG. 4).

As shown in FIG. 4 and FIG. 5, in the optical fiber holder 1, aplurality of sections 7 (7 a, 7 b, 7 c) capable of housing the pluralityof optical fibers in parallel respectively are formed in parallel by aninner surface (side surfaces 5 a 1, 5 a 2, lower surface 5 b) of thehousing portion 5, the lower surface 3 b of the first lid 3, and theprotrusion 6 when the first lid 3 is closed with respect to the holderbody 2. In this case, a height (a space in the up-down direction betweenthe lower surface 5 b of the housing portion 5 and the lower surface 3 bof the first lid 3) of each of the sections 7 (7 a, 7 b, 7 c) is largerthan an outer diameter of optical fibers to be inserted, and is smallenough so that the optical fibers do not overlap with each other in theup-down direction in one section. For example, the height is (the outerdiameter of the optical fibers to be inserted +0.02) mm or above and(twice of the outer diameter of the optical fibers −0.12) mm or below.When an optical fiber having an outer diameter of 0.20 mm is inserted,the height of each of the sections 7 (7 a, 7 b, 7 c) is preferably 0.22mm or above, and 0.28 mm or below.

As shown in FIG. 1 and FIG. 2, the lower surface 3 b of the first lid 3is provided with a tapered surface 3 c which is recessed toward a rearend side (one side) of the sections 7 (7 a, 7 b, 7 c) in thelongitudinal direction. When the first lid 3 is closed, by the taperedsurface 3 c (FIG. 4), an upper surface (ceiling) of an entrance (rearend side) of the sections 7 (7 a, 7 b, 7 c) is higher toward the outsideof the sections 7. An upper portion of the protrusion 6 does notnecessarily need to be in contact with the lower surface 3 b when thefirst lid 3 is closed with respect to the holder body 2, and a spacebetween the upper portion of the protrusion 6 and the lower surface 3 bof the first lid 3 is sufficient to be narrowed so that the opticalfibers does not move freely between the respective sections 7 a, 7 b, 7c. That is, the space is narrower than the outer diameter of the opticalfibers to be inserted, more preferably (the outer diameter of theoptical fibers to be inserted −0.02) mm or below. For example, when theoptical fiber having an outer diameter of 0.20 mm is inserted, the spaceis less than 0.20 mm, preferably 0.18 mm or below.

Further, in the first embodiment, the optical fiber holder 1 includes asecond lid 4. The second lid 4 is rotatably connected to the holder body2 via a hinge portion 4 a and can be opened and closed with respect tothe holder body 2. The hinge portion 3 a and the hinge portion 4 a arerotatable separately, and the first lid 3 and the second lid 4 can beopened and closed individually. A lower surface 4 b of the second lid 4is provided with protruding portions 4 c 1, 4 c 2 at portionscorresponding to the housing portion 5 when the second lid 4 is closedwith respect to the holder body 2 (FIG. 6). The second lid 4 is a lidthat functions such that the plurality of optical fibers inserted intothe sections 7 can be held in the housing portion 5 by the lowersurfaces of the protruding portions 4 c 1, 4 c 2 and the lower surface 5b of the housing portion 5.

The holder body 2 includes a section outer protrusion 8 provided so asto be continuous from the protrusion 6 on one side (rear side) outsidethe sections 7 in the housing portion 5, and widening side surfaces 5 d1, 5 d 2 are provided on both side surfaces 5 c 1, 5 c 2 on the innerside of the housing portion 5 on the rear side outside the sections 7such that the widening side surfaces 5 d 1, 5 d 2 are respectivelycontinuous from side surfaces 5 a 1, 5 a 2 of the sections 7 a, 7 c onboth ends of the plurality of sections 7. The widening side surfaces 5 d1, 5 d 2 have a shape in which a space between the widening sidesurfaces (5 d 1 and 5 d 2) is extended as being away from the sections 7along the longitudinal direction of the housing portion 5. Theprotruding portion 4 c 1 of the second lid 4 is provided at a positionthat does not abut on the section outer protrusion 8 and the wideningside surfaces 5 d 1, 5 d 2 when the second lid 4 is closed with respectto the holder body 2.

The shape of the widening side surfaces 5 d 1, 5 d 2 may be linear,curved, or a combination thereof. In addition, when an end far from thesections 7 of the widening side surfaces 5 d 1, 5 d 2 is a surfacewithout an angle (curved surface or the like), the tips of the opticalfibers is hardly hung on the end when the plurality of optical fibersare inserted into the housing portion 5.

When a plurality of protrusions 6 are included as shown in FIG. 1 andFIG. 2, the holder body 2 may be provided with a plurality of sectionouter protrusions 8. The plurality of section outer protrusions 8 areprovided, for example, in a shape in which a space between adjacentsection outer protrusions 8 a and 8 b is extended as being away from thesections 7 along the longitudinal direction of the housing portion 5.

Method of Using the Optical Fiber Holder According to the FirstEmbodiment

Next, an example of a method of using the optical fiber holder accordingto the first embodiment is described with reference to FIG. 1 to FIG.10.

The plurality of optical fibers used in this example are, for example, a12-core optical fiber ribbon 10 including a plurality of optical fibercore wires 11 a to 11 l shown in FIG. 7. The plurality of optical fibercore wires 11 a to 11 l are disposed in parallel in a directionorthogonal to respective longitudinal directions, and are collectivelycoated with a tape resin 12.

First, a tip end side of the optical fiber ribbon 10 is split into threeoptical fiber ribbons 10A, 10B, 10C for four cores (see FIG. 8). Then,the tape resin 12 on respective tip sides of the optical fiber ribbons10A, 10B, 10C is removed, and the optical fiber core wires 11 a to 11 lare exposed by a predetermined length. The predetermined length is alength that makes fusion connection possible by the fusion machine orthe like.

The optical fiber holder 1 described in FIG. 1 to FIG. 3 is in a statein which the first lid 3 is closed with respect to the holder body 2 asshown in FIG. 4. In the optical fiber holder 1 in the state shown inFIG. 4, the optical fiber ribbons 10 are inserted into the housingportion 5 from the rear side end 2 a of the holder body 2 with a sidewhere the optical fiber core wires 11 a to 11 l are exposed as abeginning. Since the optical fiber ribbon 10 of which the tip end sideis described above includes three optical fiber ribbons 10A, 10B, 10C,the optical fiber ribbon 10A is inserted between the widening sidesurface 5 d 1 and the section outer protrusion 8 a outside the sections7 of the housing portion 5. The optical fiber ribbon 10B is insertedbetween the outer section protrusion 8 a and the outer sectionprotrusion 8 b. The optical fiber ribbon 10C is inserted between thesection outer protrusion 8 b and the widening side surface 5 d 2.

Further, when the optical fiber ribbon 10 is pushed from the rear side,the optical fiber ribbons 10A, 10B, 10C are inserted into the sections 7a, 7 b, 7 c respectively and protrude from the front side end 2 b of theholder body 2, and are in a state shown in FIG. 8. In FIG. 8, crosssections in the sections 7 a, 7 b, 7 c are as shown in FIG. 9.

Further, from the state shown in FIG. 8, since the second lid 4 isclosed with respect to the holder body 2 (see FIG. 6), the optical fiberribbon 10 (optical fiber ribbons 10A, 10B, 10C) is held by beingsandwiched by lower surfaces of the protruding portions 4 c 1, 4 c 2 ofthe second lid 4 and the lower surface 5 b of the housing portion 5.Accordingly, it is possible to prevent the optical fiber ribbon 10(optical fiber ribbons 10A, 10B, 10C) from being easily detached fromthe optical fiber holder 1.

Further, in the optical fiber holder 1, since the space between theadjacent section outer protrusions 8 a and 8 b is wider as being awayfrom the sections along the longitudinal direction of the housingportion 5, a width W2B of an entrance (between ends of the section outerprotrusions 8 a, 8 b) for inserting the optical fiber ribbon 10B iswider than a width W1B of the section 7 b between the adjacentprotrusions 6 a, 6 b.

Further, in the optical fiber holder 1, a space between the wideningside surfaces (5 d 1 and 5 d 2) is extended as being away from thesections 7 along the longitudinal direction of the housing portion 5.Accordingly, the width W2A of an entrance (between the widening sidesurface 5 d 1 and an end of the section outer protrusion 8 a) forinserting the optical fiber ribbon 10A and a width W2C of an entrance(between the widening side surface 5 d 2 and an end of the section outerprotrusion 8 b) for inserting the optical fiber ribbon 10C can be widerthan a width W1A of the section 7 a and a width W1C of the section 7 crespectively even if the width W2B between ends of the section outerprotrusions 8 a, 8 b is extended as described above.

Therefore, even when the widths of the sections 7 (7 a, 7 b, 7 c) arenot much with respect to the widths of the optical fiber ribbons (10A,10B, 10C) to be inserted, since the widths (W2A, W2B, W2C) of theentrances are wider than the widths (W1A, W1B, W1C) of the sections 7 (7a, 7 b, 7 c), the optical fiber ribbons (10A, 10B, 10C) is easilyinserted from the entrances.

In the lower surface 3 b of the first lid 3 of the optical fiber holder1, when the first lid 3 is closed, the tapered surface 3 c is providedwhere upper surfaces (ceilings) of entrances (rear end sides) of thesections 7 (7 a, 7 b, 7 c) are higher toward the outside of the sections7. Therefore, in the sections 7 (7 a, 7 b, 7 c), since the entrance(rear end side) portions are extended upward from the interior, theoptical fiber ribbons (10A, 10B, 10C) are easily inserted.

As described above, FIG. 10 shows a perspective view of a portion of theoptical fiber ribbon 10 held in the optical fiber holder 1 whichprotrudes from the front side end 2 b of the holder body. The opticalfiber ribbons 10A and 10B are aligned such that a gap d1 correspondingto the width of the protrusion 6 a opens. The optical fiber ribbons 10Band 10C are aligned such that a gap d2 corresponding to the width of theprotrusion 6 b opens. In this example, since the widths of theprotrusions 6 a and 6 b are the same, d1=d2.

The tip end sides of the optical fiber ribbons 10A, 10B, 10C are in astate in which the optical fiber core wires are exposed by peeling offthe tape resin 12 separately and the twelve optical fiber core wires 11a to 11 l are arranged in parallel, and in this state, the tip end sidescan be fused with other optical fibers using the fusion machine or thelike.

Here, a problem when the plurality of optical fiber core wires arefusion connected with each other is described with reference to thedrawings. In the following explanatory drawings, a pattern diagram ismade where an 8-core optical fiber ribbon is assumed for the explanationto be easily understood.

The fusion machine or the like which fuses the optical fiber ribbonswith each other usually has a structure in which each of the opticalfiber core wires is placed and fused in the V groove, and as shown inFIG. 11A, a pitch Pv of V grooves is set to be equal to an arrangementpitch P25 of the optical fiber core wires 21 a to 21 h.

Usually, an outer diameter of the used optical fiber core wire is 0.25mm, and the arrangement pitch of the optical fiber ribbons arranged inparallel without a gap is 0.25 mm. Therefore, the pitch of the V groovesof the fusion machine or the like is usually 0.25 mm.

However, when the fusion machine or the like with the pitch of the Vgrooves of 0.25 mm is used to fuse the optical fiber ribbons differentfrom 0.25 mm of the arrangement pitch, the following problems occur.

In an example shown in FIG. 11B, an arrangement pitch P20 of the opticalfiber core wires 21 a to 21 h is 0.20 mm, which is narrower than thepitch Pv (0.25 mm) of the V grooves. Therefore, when a center of thearrangement of the optical fiber core wires 21 a to 21 h is aligned to aV groove top VC at a center position in a parallel width direction,positions of the V grooves and positions of the optical fiber core wiresare shifted toward an end of the arrangement of the optical fiber corewires. Therefore, in the example shown in FIG. 11B, the optical fibercore wires 21 a and 21 h at two ends do not enter the V grooves in whichthe optical fiber core wires 21 a and 21 h should be put.

Therefore, inventors of the present invention have invented aconfiguration of the optical fiber holder in which the optical fiberribbons can be arranged in parallel so that all of the optical fibercore wires can be reliably placed in the V grooves with respect to the Vgrooves with an arrangement pitch different from the arrangement pitchof the optical fiber ribbons.

That is, in a case of a configuration in which the optical fiber ribbonsare divided into a plurality of groups and the sections through thegroups are formed in parallel, since there is a space between adjacentsections in the sections, the optical fiber ribbons inserted into therespective sections are arranged in parallel at the space for eachgroup.

If the space for each group is appropriate, even if the arrangementpitch of the optical fiber ribbons is somewhat shifted from the pitch ofthe V grooves of the fusion machine or the like, since only one opticalfiber core wire that should enter each V groove abuts on an inclinedsurface of the V grooves of the fusion machine or the like and fits intothe V grooves along the inclined surface, one optical fiber core wirecan be placed in each V groove.

The inventors have further studied a range of the space for each of thegroups.

As shown in FIG. 12A, when a center position TC1 of a group T1 coincideswith a V groove top VC2 in the center of four V grooves V1 to V4 on theleft side at a space L1 from an adjacent group T2 and the group T2 alsocoincides with a V groove top VC6 in the center of four V grooves V5 toV8 on the right side in the same way, all of the optical fiber corewires 21 a to 21 h can be placed one by one in the V grooves V1 to V8.

As shown in FIG. 12B, when the optical fiber ribbons are divided intothe plurality of groups and L2 is narrower than a space at which thesections through the groups are formed in parallel, the center of theoptical fiber core wire 21 a at the left end of the group T1 coincideswith a V groove top VC1, and the center of the optical fiber core wire21 h at the right end of the optical fiber ribbon T2 coincides with a Vgroove top VC7. Therefore, the optical fiber core wire 21 a may notenter a V groove V1 while the optical fiber core wire 21 a should be putinto the V groove V1, and the optical fiber core wire 21 h may not entera V groove V8 while the optical fiber core wire 21 h should be put intothe V groove V8. Further, when the space is narrower than L2, thecenters of the optical fiber core wires 21 a, 21 h are located on sidesof adjacent V grooves (V2, V7) and do not enter the V grooves (V1, V8)while the optical fiber core wires 21 a, 21 h should be put into the Vgrooves (V1, V8).

As shown in FIG. 12C, when a space between the groups of the opticalfiber ribbons is set to be wider than the above L1, and at a time whenthe space reaches a space L3, the center of the optical fiber core wire21 d at the right end of the group T1 coincides with a V groove top VC3,and the center of the optical fiber core wire 21 e at the left end ofthe group T2 coincides with a V groove top VC5. Therefore, the opticalfiber core wire 21 d may not enter a V groove V4 while the optical fibercore wire 21 d should be put into the V groove V4, and the optical fibercore wire 21 h may not enter a V groove V5 while the optical fiber corewire 21 h should be put into the V groove V5. Further, when the space iswider than L3, the centers of the optical fiber core wires 21 d, 21 eare located on sides of adjacent V grooves (V3, V6) and do not enter theV grooves (V4, V5) while the optical fiber core wires 21 d, 21 e shouldbe put into the V grooves (V4, V5).

From the above consideration, the width of the protrusion 6 in theoptical fiber holder 1 in this embodiment is preferably set to L2 orabove and L3 or below. For example, when the optical fiber ribbons (orthe plurality of optical fiber core wires) with a pitch of 0.20 mm areplaced in the V grooves of the fusion machine or the like with a pitchof 0.25 mm, the width of the protrusion is preferably 0.17 mm or aboveand 0.27 mm or below. Accordingly, when optical fiber core wires with apitch of 0.20 mm are placed in the V grooves of the fusion machine orthe like with a pitch of 0.25 mm, only one optical fiber core wire abutson an inclined surface of each V groove and fits into the V groove alongthe inclined surface, so one optical fiber core wire can be placed ineach V groove.

The space between the center position TC1 of the group T1 of the opticalfiber ribbons and the center position TC2 of the group T2 of the opticalfiber ribbons corresponds to a distance between the centers of theadjacent sections 7 (7 a and 7 b or 7 b and 7 c) in the optical fiberholder 1 in this embodiment.

For example, when the space between TC1 and TC2 in FIG. 12A is widerthan the state in FIG. 12C, V grooves in which the optical fiber corewires do not enter are formed in the center. When the space between TC1and TC2 is narrowed and narrower than the state in FIG. 12B, V groovesin which the optical fiber core wires do not enter are formed at theend.

Therefore, for example, when the optical fiber ribbons (or the pluralityof optical fiber core wires) with a pitch of 0.20 mm is placed in the Vgrooves of the fusion machine or the like with a pitch of 0.25 mm, thedistance between the centers of the adjacent sections 7 is preferablyset to 0.95 mm or above and 1.05 mm or below. Accordingly, by preventingformation of V grooves in which the optical fiber core wires do notenter, only one optical fiber core wire abuts on an inclined surface ofeach V groove and fits into the V groove along the inclined surface, soone optical fiber core wire can be placed in each V groove.

Second Embodiment

An optical fiber holder according to a second embodiment is described.

As shown in FIG. 13 and FIG. 14, an optical fiber holder 31 according tothe second embodiment includes a holder body 32, a first lid 33, asecond lid 34, and a third lid 41. The holder body 32 includes a housingportion 35 capable of housing the plurality of optical fibers (see FIG.7 to FIG. 10) such as a 12-core optical fiber ribbon. The housingportion 35 is a linear groove-shaped recess provided on an upper surface32 c of the holder body 32 from one end (front side end 32 b) of theholder body 32 in a longitudinal direction to the other end (rear sideend 32 a).

The first lid 33, the second lid 34, and the third lid 41 are providedat a predetermined space in order from the front side end 32 b in thelongitudinal direction of the holder body 32. The first lid 33 isrotatably connected to the holder body 32 via a hinge portion 33 a andcan be opened and closed with respect to the holder body 32. In the sameway, the second lid 34 is rotatably connected to the holder body 32 viaa hinge portion 34 a and can be opened and closed with respect to theholder body 32. In the same way, the third lid 41 is rotatably connectedto the holder body 32 via a hinge portion 41 a and can be opened andclosed with respect to the holder body 32.

As shown in FIG. 14 to FIG. 16, the housing portion 35 includes at leastone protrusion 36 on a side of the front side end 32 b including aposition where the housing portion 35 is covered when the first lid 33and the second lid 34 are closed. The protrusion 36 is provided suchthat a longitudinal direction of the protrusion 36 is in parallel withan inner surface 35 b of the housing portion 35 along the longitudinaldirection of the holder body 32, and in the second embodiment, aplurality of protrusions 36 a, 36 b are provided linearly to the frontside end 32 b in the holder body 32. Grooves 37 a, 37 b, 37 c areprovided with a constant groove width, which are capable to house theplurality of optical fibers in parallel respectively between theprotrusions 36 a, 36 b and the inner surfaces 35 b on two sides of thehousing portion 35. As described above, since the protrusions 36 a, 36 bare linearly provided, the grooves 37 a, 37 b, 37 c are also formedlinearly along the longitudinal direction of the holder body 32.

The housing portion 35 includes wide grooves where the protrusion 36 isnot provided on a side of the rear side end 32 a including a coveredposition when the third lid 41 is closed.

Further, the upper surface 32 c of the holder body 32 includes regionshaving different heights from the bottom surface 35 a of the housingportion 35 (see FIG. 13). In the upper surface 32 c, a region 32 dbetween a place where the first lid 33 is closed and a place where thesecond lid 34 is closed and a region 32 e between a place where thesecond lid 34 is closed and a place where the third lid 41 is closed arehigher than the other regions, and the height of the regions 32 b and 32e is 0.3 mm in this example. There is a place where the protrusions 36a, 36 b have a different height (height from the bottom surface 35 a ofthe housing portion 35). As shown in FIG. 16, in the region 32 d (seeFIG. 13 and FIG. 14), a height H1 of the protrusions 36 a, 36 b is 0.3mm higher than the other places in this example. A height H2 of theprotrusions 36 a, 36 b at other places is 0.15 mm in this example.

As shown in FIG. 16, groove widths D of the grooves 37 a, 37 b, 37 c are0.9 mm respectively in this example. Since the groove width D is 0.9 mm,for example, the size is suitable for insertion of four optical fibershaving an outer diameter of 0.20 mm.

As shown in FIG. 14, a rubber 33 b is disposed at a place where thehousing portion 35 is covered when the first lid 33 is closed. Therubber 33 b prevents the optical fibers housed in the grooves 37 a, 37b, 37 c of the housing portion 35 respectively from affecting theposture of the optical fibers and suppresses the optical fibers fromjumping out from the holder body 32.

As shown in FIG. 14, the second lid 34 is a lid for adjusting a cuttinglength of the optical fibers and confirming that the optical fibersenter the grooves 37 a, 37 b, 37 c, and the optical fibers do not movewhen not reliably entering the grooves 37 a, 37 b, 37 c. That is, thesecond lid 34 does not hold the optical fibers put in the grooves 37 a,37 b, 37 c. The second lid 34 has an R shape such that the opticalfibers are easily inserted into longitudinal ends 34 b of the holderbody 32 when the second lid 34 is closed.

As shown in FIG. 14, the third lid 41 is disposed with a rubber 41 b ata position where the housing portion 35 is covered when the third lid 41is closed. After the optical fibers are set and the first lid 33 and thesecond lid 34 are closed, the third lid 41 is also closed, and theoptical fiber ribbons are reliably held by the rubber 41 b.

Method of Using the Optical Fiber Holder According to the SecondEmbodiment

Next, an example of a method of using the optical fiber holder accordingto the second embodiment is described. The same parts as those of thefirst embodiment are not described as appropriate. For example, same asthe first embodiment, the 12-core optical fiber ribbon 10 including theplurality of optical fiber core wires 11 a to 11 l shown in FIG. 7 isused.

First, in the optical fiber holder 31, all the lids (33, 34, 41) areopened. The tape resin 12 on tip sides of the optical fiber ribbon 10 isremoved, and the optical fiber core wires 11 a to 11 l are exposed andinserted into the housing portion 35 from the above of the holder body32.

Next, while handling the optical fiber core wires 11 a to 11 l with, forexample, a ball of a finger, four of the optical fiber core wires areinserted into each of the grooves 37 a, 37 b, 37 c (for example, theoptical fiber cores 11 a to 11 d are put in the groove 37 a, the opticalfiber cores 11 e to 11 h are put in the groove 37 b, and the opticalfiber cores 11 i to 11 l are put in the groove 37 c). If four opticalfiber ribbons are inserted into each groove, it is confirmed that thesecond lid 34 is closed to move the optical fiber ribbon 10 back andforth in the longitudinal direction of the holder body 32, and theoptical fiber core wires do not overlap and four optical fiber ribbonsenter each of the groove portions 37 a, 37 b, 37 c reliably. If theabove confirmation is made, the optical fiber ribbon 10 is pressed fromthe rear side until the optical fiber protruding from the front side end32 b of the holder body 32 has an appropriate cutting length, and forexample, is in a state shown in FIG. 17. Then, the first lid 33 and thethird lid 41 are closed, and all the lids (33, 34, 41) are closed (seeFIG. 18). As in the first embodiment, the tip end side of the opticalfiber ribbon 10 is in a state in which twelve optical fiber core wires11 a to 11 l are arranged in parallel, and can be fused with anotheroptical fiber using the fusion machine or the like in this state.

In the optical fiber holder 31 of the second embodiment, even in a casewhere the width of the grooves 37 a, 37 b, 37 c is not much large withrespect to the width of a predetermined number (for example, four) ofoptical fibers, it is possible to view that a predetermined number (forexample, four) of optical fibers enter each of the grooves 37 a, 37 b,37 c from the upside of the holder body 32.

In the optical fiber holder 31 of the second embodiment, the second lid34 is closed to move the optical fiber ribbon 10 back and forth in thelongitudinal direction of the holder body 32, and thus it is possible toconfirm that the optical fibers do not overlap and a predeterminednumber (for example, four) of the optical fibers enter each of thegroove portions 37 a, 37 b, 37 c reliably.

Further, since the optical fiber holder 31 of the second embodiment doesnot need to provide an introduction portion of the optical fiber ribbonin the front-rear direction, the grooves 37 a, 37 b, 37 c can belengthened in the longitudinal direction of the holder body 32, and aneffect of suppressing the inclination of the optical fiber set in theoptical fiber holder 31 is increased.

Further, since the height H of the protrusions 36 a, 36 b is set to 0.3mm at the maximum, a guide function can be obtained and the operationcan be easy when the plurality of optical fibers (optical fiber corewires) having an outer diameter of 0.20 mm for example are put into thegrooves while handling with a ball of a finger. The depth of the grooves37 a, 37 b, 37 c is 0.3 mm at maximum. If the groove is deep, it maybecome difficult to overlap and set the optical fibers up and down inthe groove, but in this example, since the grooves 37 a, 37 b, 37 c havea depth of 0.3 mm or below, overlapping of the optical fibers in thegroove can be suppressed.

Further, in this example, since the depth of the grooves 37 a, 37 b, 37c in a portion where the first lid 33 and the third lid 41 are closed is0.15 mm, the optical fiber core wire having an outer diameter of 0.20 mmcan be pressed and reliably held with the rubber 33 b and the rubber 41b.

Although the present invention has been described in detail withreference to particular embodiments, it is apparent to those skilled inthe art that various changes and modifications can be made withoutdeparting from the spirit and scope of the present invention. Thenumbers, positions, shapes, and the like of components described aboveare not limited to the above embodiments, and can be changed to suitablenumbers, positions, shapes, and the like on carrying out the presentinvention.

For example, in each of the above embodiments, a method of using anormal optical fiber ribbon for an optical fiber holder has beendescribed, and in a state in which the plurality of optical fiber corewires are arranged in parallel, an intermittent-connection-type opticalfiber ribbon may be used such that the intermittent-connection-typeoptical fiber ribbon includes connecting portions in which adjacentoptical fiber core wires are connected to each other and non-connectingportions in which adjacent optical fiber core wires are not connected toeach other, and connecting portions and the non-connecting portions areprovided intermittently in the longitudinal direction.

The optical fiber ribbon may have the number of cores other than twelvecores as long as the optical fiber ribbon has eight cores or more.

The plurality of optical fiber cores arranged in parallel with theoptical fiber holder may be used.

DESCRIPTION OF REFERENCE NUMERALS

-   -   1 optical fiber holder    -   2 holder body    -   2 a rear side end    -   2 b front side end    -   2 c upper surface    -   3 first lid (lid)    -   3 a hinge portion    -   3 b lower surface    -   3 c tapered surface    -   4 second lid    -   4 a hinge portion    -   4 b lower surface    -   4 c 1, 4 c 2 protruding portion    -   5 housing portion    -   5 a 1, 5 a 2 side surface    -   5 b lower surface    -   5 c 1, 5 c 2 side surface    -   5 d 1, 5 d 2 widening side surface    -   6, 6 a, 6 b protrusion    -   7, 7 a, 7 b, 7 c section    -   8, 8 a, 8 b section outer protrusion    -   10 optical fiber ribbon    -   11 a to 11 l optical fiber core wire    -   10A, 10B, 10C optical fiber ribbon    -   21 a to 21 h optical fiber core wire    -   T1, T2 group (of optical fiber ribbons)    -   31 optical fiber holder    -   32 holder body    -   32 a rear side end    -   32 b front side end    -   32 c upper surface    -   32 d, 32 e region    -   33 first lid    -   33 a, 34 a, 41 a hinge portion    -   33 b, 41 b rubber    -   34 second lid    -   34 b end    -   35 housing portion    -   35 a bottom surface    -   35 b inner surface    -   36, 36 a, 36 b protrusion    -   37 a, 37 b, 37 c groove    -   41 third lid

1: An optical fiber holder comprising: a holder body; a first lid; and asecond lid, wherein the holder body includes a housing portion that isconfigured to house a plurality of optical fibers, the holder bodyincludes at least one linear protrusion along a longitudinal directionof the holder body in the housing portion, the housing portion includesa plurality of grooves that include a constant groove width and that isconfigured to house the plurality of optical fibers in parallelrespectively between the protrusion and an inner surface of the housingportion, the plurality of optical fibers are configured to be held inparallel respectively in the plurality of grooves in a state where thefirst lid is closed with respect to the holder body, and the pluralityof optical fibers are configured to be housed in a movable state wherethe plurality of optical fibers are movable in parallel respectively inthe plurality of grooves, in a state where the second lid is closed withrespect to the holder body. 2: The optical fiber holder according toclaim 1, wherein a height of the protrusion is 0.15 mm or above and 0.3mm or below. 3: The optical fiber holder according to claim 1, furthercomprising: a third lid, wherein the housing portion includes widegrooves and does not provide with the protrusion at a covered positionin a state where the third lid is closed respect to the holder body. 4:An optical fiber holder comprising: a holder body; and a lid, whereinthe holder body includes a housing portion that is configured to house aplurality of optical fibers, the holder body or the lid includes atleast one protrusion that is capable of being disposed in the housingportion, and a plurality of sections are formed in parallel such thatthe plurality of sections are configured to house the plurality ofoptical fibers in parallel respectively by an inner surface of thehousing portion, a lower surface of the lid, and the protrusion in astate where the lid is closed with respect to the holder body. 5: Theoptical fiber holder according to claim 4, wherein a width of theprotrusion is 0.17 mm or above and 0.27 mm or below. 6: The opticalfiber holder according to claim 4, wherein a distance between centers ofadjacent sections is 0.95 mm or above and 1.05 mm or below. 7: Theoptical fiber holder according to claim 4, wherein the holder bodyincludes a section outer protrusion that is provided to be continuousfrom the protrusion on one side of the housing portion outside thesection, widening side surfaces are provided on two both side surfacesin an inner side of the housing portion on one side outside the sectionsuch that the widening side surfaces are respectively continuous fromside surfaces of sections, among the plurality of sections, on both sidesurfaces in the inner side of the housing portion, and the widening sidesurfaces have a shape in which a space between the widening sidesurfaces is extended along a longitudinal direction of the housingportion as being away from the section. 8: The optical fiber holderaccording to claim 4, comprising: a plurality of the protrusions,wherein the holder body includes, on one side outside the section of thehousing portion, a plurality of section outer protrusions provided so asto be continuous from the plurality of the protrusions respectively, andthe plurality of section outer protrusions have a shape in which a spacebetween adjacent section outer protrusions is extended along alongitudinal direction of the housing portion as being away from thesection. 9: The optical fiber holder according to claim 4, wherein thelid is provided with a tapered surface where the lower surface isrecessed on one side end of the section in a longitudinal direction. 10:The optical fiber holder according to claim 4, further comprising: asecond lid, wherein a plurality of optical fibers housed in the housingportion and inserted into the section are configured to be held in thehousing portion in a state where the second lid is closed with respectto the holder body.